The present disclosure relates to semiconductor circuits, and more particularly, to storage devices which include a nonvolatile memory device and a controller.
A storage device is a device that stores data under control of a host device. A few examples of a host device include a computer, a smartphone, and a smart pad or tablet. In generally, one class of storage devices stores data on a magnetic (or optical) disk such as a hard disk drive (HDD), while another class of storage devices stores data on a semiconductor memory such as a solid state drive (SSD) or a memory card.
Nonvolatile semiconductor memory devices retain stored data in absence of supplied power, and examples thereof include read-only memory (ROM), a programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM), flash memory, phase-change RAM (PRAM), magnetic RAM (MRAM), resistive RAM (RRAM), ferroelectric RAM (FRAM), and the like.
As semiconductor manufacturing technologies continue to advance, storage devices of increased integration and higher memory capacity are realized. However, the resultant reductions in scale and changes in structures present significant challenges in avoiding degradations in reliability of storage devices.